Electricity was first put to commercial and residential use in the United States in the late 1800's, to solve the age-old problem of darkness. Ever since, the ability of electrical current to deliver an electric shock to a person or animal has been recognized. Shortly thereafter, the non-lethal applications of electricity for use in encouraging the behavior of animals was commercially implemented. The electric cattle prod is perhaps the best known of those devices. Today, however, electricity is used in many ways with animals. As just a few examples, electric fences are used to keep farm animals in and predators out, and dog trainers use electrical stimulus in dog collars to assist with dog training.
An age-old problem that has been perplexing mankind since long before the discovery and harnessing of electricity is the propensity of pests in general, but particularly birds, to land in areas where their human neighbors would prefer they did not. An incredible array of devices have been used to dissuade birds from landing or roosting in areas undesirable to humans. Metallic spikes, coil or rotating devices, sound-emitting devices, imitation predators, and even real predators, are just a few examples of bird deterrent devices that have been used.
At some point in the evolution of bird deterrent devices lethal and non-lethal electrical shock began to be employed as a bird deterrent. One device of this type is shown in U.S. Pat. No. 4,299,048. In one embodiment, a pair of copper wires connected to a power source are embedded in opposite sides of a cable of appropriate diameter such that when the birds of choice (in this case, starlings) land on the cable, their feet touch both wires, closing the circuit and thereby delivering a lethal shock to the birds.
U.S. Pat. No. 6,283,064 discloses another version of a bird and pest deterrent device in which a pair of crimped copper wires are appropriately spaced apart so that the bird's or other pest's feet will touch both wires, resulting in a short circuit and delivering a shock to the bird or other pest.
Other devices for carrying electric charges for discouraging birds and other pests are described in U.S. Pat. Nos. 3,294,893; 3,366,854; 3,717,802; 4,299,048; and 5,850,808. A common idea to all of these devices is the concept of appropriately spaced-apart electrical contacts which will both be connected by the bird's (or other pest's) feet (or other part of their anatomy) so as to deliver the appropriate electric shock.
U.S. Pat. No. 7,481,021 to Riddell uses a flexible track and replaces the typically-used wire with a braided conductive element that may be sewn to the base. This configuration helps alleviate the problem of the wire separating from its base when the track is bent to fit certain surfaces.
Some other devices and methods are disclosed, for example, in the following: U.S. Pat. Nos. 8,015,747; 8,020,340; and international applications WO 95/08915; and WO 2012/040009.
While all of these devices work at least initially to a degree in some installations, the designs of the current systems exhibit problems. One problem is the unwanted shorting of the conductive wires due to an accumulation of water beneath the track or base. For example, the stitching used to secure the metal braids or metal mesh to flexible polyvinyl chloride (“PVC”) extrusions can create problems with respect to arcing to some surface materials. Occasionally, the sewing machine's needle breaks a wire strand and pushes it through the bottom of the base. When the wire is electrified these strands can arc with a wet or metal surface below. In addition, water that pools underneath the track can be absorbed by the thread used to sew the conductive wire to the base, creating a conductor and causing an arc to the surface below. Raising the stitch off the surface by means of a groove does not eliminate this problem.
While the existing animal deterrents are useful to a degree, they still suffer from certain drawbacks that may cause undesired short circuiting of the device. Therefore, there exists a need in the art for an improved electrical shock deterrent device that solves or at least alleviates some or all of these problems.